Relapsed leukemia following initial therapeutic response and remission is difficult to treat and causes high patient mortality. Leukemia relapse is due to residual quiescent leukemia cells that escape conventional therapies and later reemerge. Eliminating not only growing but quiescent leukemia cells is critical to effectively treating leukemia and preventing its recurrence. Such dual targeting therapeutic agents, however, are lacking in the clinic. To start tackling this problem, encouraged by the promising anticancer effects of a set of curcumin derivatives in our earlier studies, we examined in this work the effects of a 4-arylmethyl curcumin derivative (C212) in eliminating both growing and quiescent leukemia cells. We analyzed the effects of C212 on the growth and viability of growing and quiescent leukemia cells using MTS, apoptosis, cell cycle and cell tracking assays. The effects of C212 on the quiescence depth of leukemia cells were measured using EdU incorporation assay upon growth stimulation. The mechanisms of C212-induced apoptosis and deep dormancy, particularly associated with its inhibition of Hsp90 activity, were studied using molecular docking, protein aggregation assay, and Western blot of client proteins. C212, on the one hand, inhibits growing leukemia cells at a higher efficacy than curcumin by inducing apoptosis and G2/M accumulation; it, on the other hand, eliminates quiescent leukemia cells that are resistant to conventional treatments. Furthermore, C212 drives leukemia cells into and kills them at deep quiescence. Lastly, we show that C212 induces apoptosis and drives cells into deep dormancy at least partially by binding to and inhibiting Hsp90, leading to client protein degradation and protein aggregation. C212 effectively eliminates both growing and quiescent leukemia cells by inhibiting Hsp90. The property of C212 to kill quiescent leukemia cells in deep dormancy avoids the risk associated with awaking therapy-resistant subpopulation of quiescent leukemia cells during treatments, which may lead to the development of novel therapies against leukemia relapse.

中文翻译：

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姜黄素衍生物 C212 抑制 Hsp90 并消除深度休眠中生长和静止的白血病细胞

初始治疗反应和缓解后复发的白血病难以治疗并导致高患者死亡率。白血病复发是由于残留的静止白血病细胞逃脱了常规治疗，后来又重新出现。消除不仅生长而且静止的白血病细胞对于有效治疗白血病和防止其复发至关重要。然而，临床上缺乏这种双重靶向治疗剂。为了开始解决这个问题，在我们早期研究中一组姜黄素衍生物有希望的抗癌作用的鼓舞下，我们在这项工作中检查了 4-芳甲基姜黄素衍生物 (C212) 在消除生长和静止的白血病细胞方面的作用。我们使用 MTS、细胞凋亡、细胞周期和细胞追踪分析。C212 对白血病细胞静止深度的影响在生长刺激时使用 EdU 掺入测定法测量。使用分子对接、蛋白质聚集测定和客户蛋白质的蛋白质印迹研究 C212 诱导的细胞凋亡和深度休眠的机制，特别是与其抑制 Hsp90 活性相关的机制。一方面，C212 通过诱导细胞凋亡和 G2/M 积累，以比姜黄素更高的功效抑制白血病细胞的生长；另一方面，它消除了对常规治疗具有抗性的静止白血病细胞。此外，C212 驱使白血病细胞进入并在深度静止时杀死它们。最后，我们表明 C212 至少部分通过结合和抑制 Hsp90 诱导细胞凋亡并驱动细胞进入深度休眠，导致客户蛋白质降解和蛋白质聚集。C212 通过抑制 Hsp90 有效消除生长和静止的白血病细胞。C212 在深度休眠状态下杀死静止白血病细胞的特性避免了在治疗过程中唤醒静止白血病细胞抗治疗亚群的风险，这可能会导致针对白血病复发的新疗法的开发。